JP5140918B2 - Rubber composition and molded article - Google Patents

Description

The present invention relates to a rubber composition and a molded article, and more specifically, a cross-linked rubber composition having excellent workability and cross-linking, and having excellent tensile properties, wear resistance, ozone resistance and heat aging resistance. The present invention relates to a rubber composition and a molded product.

In order to improve the durability of rubber products such as tires, anti-vibration rubbers, belts, and rollers, improvements in tensile properties and wear resistance of the crosslinked rubber composition are required.
In general, in order to improve the tensile properties and wear resistance of the crosslinked rubber composition, it is effective to increase the molecular weight of the raw rubber. However, if a raw material rubber having a too high molecular weight is used, workability in a process such as kneading is remarkably lowered, and as a result, dispersibility of a reinforcing agent or the like in the obtained rubber composition is deteriorated, and the crosslinked rubber composition May cause a decrease in strength.
In view of this, attempts have been made to improve the tensile properties and wear resistance of the crosslinked rubber composition without extremely increasing the molecular weight of the raw rubber. That is, since various additives are usually contained in a rubber product, molecular design for improving the affinity with carbon black, silica and the like is performed as a method for improving a polymer component. For example, when a rubber composition using carbon black as a reinforcing agent is targeted, a styrene-butadiene (co) polymer having a polymer terminal modified or coupled with a tin compound disclosed in Patent Document 1, a patent A styrene-butadiene (co) polymer, etc., which is disclosed in Document 2 and has a polymer terminal modified with an isocyanate compound or the like is known. Similarly, when a composition using silica as a reinforcing agent is targeted, a rubber composition containing a polymer into which a functional group having an affinity for silica is introduced has been proposed. Patent Document 3 discloses a method for producing a polymer by reacting silicon tetrahalide, trihalosilane, or the like. Patent Document 4 discloses a method for producing a polymer modified with a halogenated silane compound. Further, Patent Document 5 discloses a diene rubber into which an alkylsilyl group and Patent Document 6 each have a halogenated silyl group introduced. Further, Patent Document 7 discloses a diene rubber having a tertiary amino group and an alkoxysilyl group introduced therein.
The compositions containing these polymer components are not sufficient, although some improvements in wear resistance, tensile properties, etc. are observed when they are vulcanized, respectively. Since a functional group having an affinity for silica is introduced, the processability of the rubber composition may be lowered.

JP-A-57-55912 Japanese Patent Application Laid-Open No. 61-141741 Japanese Patent Publication No.49-36957 Japanese Patent Publication No.52-5071 JP-A-1-188501 Japanese Patent Laid-Open No. 5-230286 JP 7-233217 A

An object of the present invention is to provide a rubber composition and a molded article that are excellent in processability and can be made into a crosslinked rubber composition excellent in tensile properties, abrasion resistance, ozone resistance and heat aging resistance by crosslinking. There is to do.

The present inventors arrange polymer blocks having specific structures having different hydrogenation rates (hereinafter also referred to as “hydrogenation rates”) without introducing specific functional groups in a specific ratio and in a specific order. It has been found that the above-mentioned problems can be solved by using the partially hydrogenated block copolymer.
The present invention is shown below.
[1] A rubber composition comprising a block copolymer and carbon black,
The block copolymer comprises two polymer blocks having an ethylenically unsaturated bond, and another polymer block between the polymer blocks, and the polymer block having the ethylenically unsaturated bond comprises When A ¹ and A ² (A ¹ and A ² may be the same or different) and the other polymer block is B, (A ¹ -B-A ² ) _s X Wherein s is an integer selected from 1 to 6 and X is a residue of a coupling agent.
The polymer block A ¹ is composed of a conjugated diene compound and includes a monomer unit (a11) including a 1,4-bond, and 80% or more of unsaturated bonds derived from the conjugated diene compound are ethylenically unsaturated. A polymer block included as a bond,
The polymer block B includes a monomer unit (b11) composed of a conjugated diene compound and a monomer unit (b12) composed of an aromatic vinyl compound, and 0 to 20 unsaturated bonds derived from the conjugated diene compound. % Is a polymer block containing as ethylenically unsaturated bonds,
It said polymer block A ² contains a monomer unit (a21) containing it and 1,4-linked conjugated diene compound, 80% or more of unsaturated bonds derived from the conjugated diene compound is an ethylenically unsaturated A polymer block included as a bond,
The polymer block having an ethylenically unsaturated bond has a weight average molecular weight in the range of 1,000 to 20,000,
A rubber composition wherein the weight average molecular weight of the other polymer block is in the range of 5,000 to 100,000.
[2] The total constituent amount of the polymer block having an ethylenically unsaturated bond is 1 to 80% by mass with respect to the block copolymer, and the total constituent amount of the other polymer blocks is The rubber composition according to [1], which is 99 to 20% by mass with respect to the block copolymer.
[3] The weight average molecular weight of the block copolymer is in the range of 7,000 to 1,000,000, and the ratio of the weight average molecular weight and the number average molecular weight is in the range of 1 to 5 [1] or [ 2].
[4] The conjugated diene compound used to form the polymer block A ¹ and the polymer block A ² is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro- The rubber composition according to any one of [1] to [3], which is at least one selected from 1,3-butadiene and 1,3-pentadiene.
[5] The conjugated diene compound used for forming the polymer block B is at least one selected from 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene. And
The aromatic vinyl compound used to form the polymer block B is styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropyl. The rubber composition according to any one of [1] to [4], which is at least one selected from styrene and 4-tert-butylstyrene.
[6] The rubber composition according to any one of [1] to [5], wherein the content of the carbon black is 20 to 120 parts by mass with respect to 100 parts by mass of the block copolymer.
[7] A molded product obtained by using the rubber composition according to any one of [1] to [6].
[8] A rubber composition comprising a block copolymer and silica,
The block copolymer comprises two polymer blocks having an ethylenically unsaturated bond, and another polymer block between the polymer blocks, and the polymer block having the ethylenically unsaturated bond comprises A ¹ and A ² (where A ¹ and A ² may be the same or different), and when the other polymer block is B, A ¹ -B-A ² -BA ¹ structure,
The polymer block A ¹ is a monomer unit (a11) made of a conjugated diene compound and containing a 1,4-bond, or a monomer unit made of the monomer unit (a11) and an aromatic vinyl compound. A polymer block containing both of (a12), wherein 80% or more of unsaturated bonds derived from the conjugated diene compound are contained as ethylenically unsaturated bonds;
The polymer block B includes a monomer unit (b11) composed of a conjugated diene compound and a monomer unit (b12) composed of an aromatic vinyl compound, and 0 to 20 unsaturated bonds derived from the conjugated diene compound. % Is a polymer block containing as ethylenically unsaturated bonds,
Said polymer block A ² is monomeric units containing it and 1,4-linked conjugated diene compound (a21), or consist of said monomer units (a21) and the aromatic vinyl compound monomer unit (A22) is a polymer block containing both of the unsaturated bonds derived from the conjugated diene compound and containing 80% or more of ethylenically unsaturated bonds,
The polymer block having an ethylenically unsaturated bond has a weight average molecular weight in the range of 1,000 to 20,000,
A rubber composition wherein the weight average molecular weight of the other polymer block is in the range of 5,000 to 100,000 .
[9] The total constituent amount of the polymer block having an ethylenically unsaturated bond is 1 to 80% by mass with respect to the block copolymer, and the total constituent amount of the other polymer blocks is The rubber composition according to [8], which is 99 to 20% by mass with respect to the block copolymer.
[10] The weight average molecular weight of the block copolymer is in the range of 7,000 to 1,000,000, and the ratio of the weight average molecular weight and the number average molecular weight is in the range of 1 to 5 [8] or [ 9].
[11] The conjugated diene compound used to form the polymer block A ¹ and the polymer block A ² is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro- The rubber composition according to any one of [8] to [10], which is at least one selected from 1,3-butadiene and 1,3-pentadiene.
[12] The conjugated diene compound used for forming the polymer block B is at least one selected from 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene. And
The aromatic vinyl compound used to form the polymer block B is styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropyl. The rubber composition according to any one of [8] to [11], which is at least one selected from styrene and 4-tert-butylstyrene.
[13] The rubber composition according to any one of [8] to [12], wherein the content of the silica is 20 to 140 parts by mass with respect to 100 parts by mass of the block copolymer.
[14] A molded product obtained by using the rubber composition according to any one of [8] to [13].

The block copolymer contained in the rubber composition of the present invention is a specific polymer comprising at least two polymer blocks having an ethylenically unsaturated bond and another polymer block located between the polymer blocks. since it is excellent in workability. Moreover, since the crosslinked polymer has a regular network structure by crosslinking, a crosslinked rubber composition excellent in tensile properties, abrasion resistance, ozone resistance and heat aging resistance can be obtained.

In addition, by forming the polymer blocks A ¹ , A ² and B from specific compounds, a regular cross-linked structure can be formed, and tensile properties, wear resistance, ozone resistance and heat aging can be formed. It can be set as the crosslinked rubber composition which was further excellent in property.

In the present invention, when a rubber composition containing carbon black or silica in a predetermined amount with respect to 100 parts by mass of the block copolymer is used, each physical property of the crosslinked rubber composition is particularly excellent.

The present invention will be described in detail below.
1. Block copolymer The block copolymer contained in the rubber composition of the present invention comprises two polymer blocks having an ethylenically unsaturated bond (hereinafter also referred to as “polymer block A”), and the polymer block. And at least a polymer block having a weight average molecular weight in a specific range (hereinafter also referred to as “polymer block B”).

1-1. Polymer block A
This polymer block A has at least one ethylenically unsaturated bond (carbon-carbon double bond). This ethylenically unsaturated bond may be contained in the main chain or in the side chain in the polymer block A. Furthermore, it may be included in both. Further, when this ethylenically unsaturated bond is contained in the main chain, it may be present at the end of the block copolymer.
The ethylenically unsaturated bond is derived from a conjugated diene compound. The ethylenically unsaturated bond includes a 1,4-bond , and the other can be a 1,2-bond, a 3,4-bond (vinyl bond), or the like.

Therefore, the polymer block A can have the following modes.
(1-1) Polymer block mainly containing monomer units consisting of conjugated diene compounds (1-2) Polymer mainly containing monomer units consisting of conjugated diene compounds and monomer units consisting of aromatic vinyl compounds Block (1-3) Monomer comprising a monomer unit comprising a conjugated diene compound, a monomer unit comprising an aromatic vinyl compound, and a monomer compound copolymerizable with the conjugated diene compound and the aromatic vinyl compound Polymer block mainly comprising a body unit (1-4) A monomer unit comprising a conjugated diene compound and a monomer comprising a monomer compound other than an aromatic vinyl compound and copolymerizable with the conjugated diene compound A polymer block mainly containing units.

  Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, and the like. These can be used alone or in combination of two or more. Of these, 1,3-butadiene and isoprene are preferred.

  Examples of the aromatic vinyl compound include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, and 4-tert-butylstyrene. , Divinylbenzene, vinylbenzyldimethylamine, vinylbenzyldimethylaminoethanolamine, N, N-dimethylaminoethylstyrene, 4-tert-butoxystyrene, vinylpyridine and the like. These can be used alone or in combination of two or more. Of these, styrene is preferred.

In addition, as a monomer compound copolymerizable with both the conjugated diene compound and the aromatic vinyl compound, unsaturated carboxylic acids and esters thereof (alkyl esters, alkoxy esters, hydroxyl group-containing esters, amino group-containing esters, Amide group-containing esters), vinyl cyanide compounds and the like. These can be used individually by 1 type or in combination of 2 or more types.
Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and the like.
Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

  In the above embodiment (1-1), the total amount of the monomer units composed of the conjugated diene compound is preferably 80% by mass or more, more preferably based on the total of all monomer units constituting the polymer block A. Is 90 to 100% by mass, more preferably 95 to 100% by mass.

  In the above aspect (1-2), the total amount of the monomer unit consisting of the conjugated diene compound and the monomer unit consisting of the aromatic vinyl compound is based on the total of all the monomer units constituting the polymer block A. And preferably 80% by mass or more, more preferably 90 to 100% by mass, and still more preferably 95 to 100% by mass. In addition, the arrangement | sequence order of the monomer unit which consists of a conjugated diene compound and the monomer unit which consists of an aromatic vinyl compound is not specifically limited.

  In the above aspect (1-3), the total amount of the monomer unit consisting of the conjugated diene compound and the monomer unit consisting of the aromatic vinyl compound is based on the total of all the monomer units constituting the polymer block A. Preferably, it is 80-99 mass%, More preferably, it is 90-99 mass%, More preferably, it is 95-98 mass%. An arrangement of a monomer unit comprising a conjugated diene compound, a monomer unit comprising an aromatic vinyl compound, and a monomer unit comprising a monomer compound copolymerizable with the conjugated diene compound and the aromatic vinyl compound. The order is not particularly limited.

  In the above aspect (1-4), the total amount of the monomer units composed of the conjugated diene compound is preferably 80 to 99% by mass with respect to the total of all the monomer units constituting the polymer block A. Preferably it is 90-99 mass%, More preferably, it is 95-98 mass%. The order of arrangement of the monomer unit composed of the conjugated diene compound and the monomer unit composed of the monomer compound copolymerizable with the conjugated diene compound is not particularly limited.

  Moreover, in the said aspect (1-2) and (1-3), the component amount of the monomer unit which consists of a conjugated diene compound, and the monomer unit which consists of an aromatic vinyl compound makes these total 100 mass%. In this case, it is preferably 50% by mass or more / 50% by mass or less, more preferably 52 to 97% by mass / 48 to 3% by mass, and still more preferably 57 to 92% by mass / 43 to 8% by mass. If the amount of the monomer unit composed of an aromatic vinyl compound is too large, the hardness in the case of a crosslinked polymer may be increased, and the processability when forming a rubber composition or a molded product is lowered. There is a case.

  Furthermore, in the polymer block A according to the present invention, 80% or more of the unsaturated bonds derived from the conjugated diene compound are included as ethylenically unsaturated bonds. More preferably, it is 85-100%, More preferably, it is 90-100%, Most preferably, it is 95-100%. The ethylenically unsaturated bond can be measured by IR, NMR or the like. The same applies to the following.

  As a preferable example of the above embodiment (1-1), the unsaturated bond derived from the conjugated diene compound mainly containing the monomer unit (a11) comprising a conjugated diene compound and including a 1,4-bond is used. % Or more of polymer blocks containing ethylenically unsaturated bonds. More specifically, the conjugated diene compound is isoprene, contains 80 to 100% by mass of a monomer unit composed of this isoprene, and 80% or more of the unsaturated bonds derived from this isoprene are ethylenically unsaturated bonds. Polymer blocks included are preferred. In addition, the structural amount of a more preferable monomer unit (a11) and the content rate of a more preferable ethylenic unsaturated bond are the same as the above.

  Moreover, as a preferable example of the said aspect (1-2), the monomer unit (a11) which consists of a conjugated diene compound and contains a 1, 4- bond, and the monomer unit (a12) which consists of an aromatic vinyl compound. Examples thereof include a polymer block containing mainly 80% or more of unsaturated bonds derived from a conjugated diene compound as ethylenically unsaturated bonds. More specifically, the conjugated diene compound is isoprene, contains a total of 80 to 100% by mass of monomer units composed of isoprene and monomer units composed of aromatic vinyl compounds such as styrene, and is derived from isoprene. A polymer block containing 80% or more of unsaturated bonds as ethylenically unsaturated bonds is preferred. In addition, the preferable total amount of the monomer unit (a11) consisting of a conjugated diene compound (isoprene) and the monomer unit (a12) consisting of an aromatic vinyl compound, more preferable constituent amount of each monomer unit and more preferable ethylene. The content of the unsaturated bond is the same as described above.

  The weight average molecular weight of the polymer block A is in the range of 1,000 to 20,000, more preferably 3,000 to 18,000, and still more preferably 5,000 to 15,000. If the weight average molecular weight is too small, the chain length of the polymer block A is too short, so that when the crosslinked polymer is used, sufficient crosslinking cannot be formed, so that tensile strength, fracture strength, and wear resistance are reduced. May be significantly reduced. On the other hand, if the weight average molecular weight is too large, the tensile strength, fracture strength, and abrasion resistance become the same as when a general diene polymer is used, and the improvement effect may not be exhibited. The weight average molecular weight is based on polystyrene conversion using gel permeation chromatography (GPC). The same applies to the following.

  The total composition amount of the polymer block A is preferably 1 to 80% by mass, more preferably 3 to 60% by mass, and still more preferably 5 to 40% by mass with respect to the block copolymer. If the amount of the polymer block A is too large, the tensile strength, fracture strength, and wear resistance of the crosslinked polymer are the same as when a general diene polymer is used. It may not be demonstrated.

The block copolymer includes at least two of the polymer blocks A and a polymer block B described later between these polymer blocks. The plurality of polymer blocks A have the same configuration. It may be a different configuration.

1-2. Polymer block B
This polymer block B includes a monomer unit composed of a conjugated diene compound and a monomer unit composed of an aromatic vinyl compound, and 0 to 20% of the unsaturated bonds derived from the conjugated diene compound are ethylenically unsaturated bonds. It is a polymer block contained as
It is preferable that the polymer block B mainly contains a methylene group (—CH ₂ —). In this methylene group, some or all of the hydrogen atoms are halogen atoms, hydroxyl groups, amino groups, organic groups (hydrocarbon groups such as alkyl groups, cycloalkyl groups, phenyl groups; halogen atoms, hydroxyl groups, amino groups). Or a modified group substituted with a hydrocarbon group substituted with an amide group or the like, a pyridyl group, or the like. Accordingly, the polymer block B includes a main chain formed by the methylene group and the like being continuous.
In addition, when the said polymer block B contains an ethylenically unsaturated bond, you may include in the principal chain of a polymer block, and may include it in a side chain.

It said polymer block B is state, and are not formed from a compound containing a conjugated diene compound and an aromatic vinyl compound may be the following embodiments.
(2 1) composed of a conjugated diene compound consisting monomer unit and an aromatic vinyl compound monomer unit mainly comprises polymer block (2-2) and monomer units comprising a conjugated diene compound, aromatic vinyl A polymer block mainly comprising a monomer unit comprising a compound and a monomer unit comprising a monomer compound copolymerizable with a conjugated diene compound and an aromatic vinyl compound

  As each monomer compound, those exemplified in the description of the polymer block A can be preferably used, and each monomer compound can be used alone or in combination of two or more.

In the above aspect (2 1), the total amount of the monomer unit formed by a monomer unit and an aromatic vinyl compound comprising a conjugated diene compound, based on the combined total of all monomer units constituting the polymer block B And preferably 80% by mass or more, more preferably 90 to 100% by mass, and still more preferably 95 to 100% by mass. The order of arrangement of the monomer unit composed of the conjugated diene compound and the monomer unit composed of the aromatic vinyl compound is not particularly limited. For example, the monomer unit composed of the aromatic vinyl compound is randomly selected in the polymer block. The polymer block B may be an arrayed one or a single chain formed by a monomer unit made of an aromatic vinyl compound.

In the above aspect (2-2), the total amount of the monomer unit formed by a monomer unit and an aromatic vinyl compound comprising a conjugated diene compound, based on the combined total of all monomer units constituting the polymer block B Preferably, it is 80-99 mass%, More preferably, it is 90-99 mass%, More preferably, it is 95-98 mass%. An arrangement of a monomer unit comprising a conjugated diene compound, a monomer unit comprising an aromatic vinyl compound, and a monomer unit comprising a monomer compound copolymerizable with the conjugated diene compound and the aromatic vinyl compound. The order is not particularly limited.

In the above embodiment (2 1) and (2 2), configuration of the monomer units comprising a monomer unit and an aromatic vinyl compound comprising a conjugated diene compound, and these total 100 wt% In this case, it is preferably 40 to 98% by mass / 60 to 2% by mass, more preferably 50 to 95% by mass / 50 to 5% by mass, and still more preferably 55 to 92% by mass / 45 to 8% by mass. If the amount of the monomer unit composed of an aromatic vinyl compound is too large, the hardness in the case of a crosslinked polymer may be increased, and the processability when forming a rubber composition or a molded product is lowered. There is a case.

  Furthermore, as described above, the polymer block B according to the present invention contains 0 to 20% of unsaturated bonds derived from the conjugated diene compound as ethylenically unsaturated bonds. More preferably, it is 0-15%, More preferably, it is 0-12%, Most preferably, it is 1-10%.

Preferred examples of the above embodiment (2 1), comprising mainly a monomer unit (b11) and an aromatic vinyl compound monomer unit (b12) containing it and 1,2-bond of a conjugated diene compound And the polymer block etc. in which 0-20% of the unsaturated bond derived from a conjugated diene compound is contained as an ethylenically unsaturated bond are mentioned. More specifically, the conjugated diene compound is 1,3-butadiene, and a monomer unit composed of 1,3-butadiene and a monomer unit composed of an aromatic vinyl compound such as styrene are added in a total of 80 to A polymer block containing 100% by mass and containing 0 to 20% of unsaturated bonds derived from 1,3-butadiene as ethylenically unsaturated bonds is preferred. In addition, the preferable total amount of the monomer unit (b11) consisting of a conjugated diene compound (1,3-butadiene) and the monomer unit (b12) consisting of an aromatic vinyl compound, and more preferable constituent amounts of each monomer unit. And more preferable content of the ethylenically unsaturated bond is the same as above.

In the case of the composition containing carbon black, the weight average molecular weight of the polymer block B is in the range of 5,000 to 100,000, preferably 20,000 to 95,000, more preferably 35,000 to 85,000. Also, in the case of the composition containing silica is in the range of 5,000 to 100,000. If this weight average molecular weight is too small, the tensile strength, fracture strength, and wear resistance of the crosslinked polymer will be the same as when a general diene polymer is used, and the improvement effect may not be exhibited. is there. On the other hand, if the weight average molecular weight is too large, the tensile strength, fracture strength, and wear resistance may decrease.

  The total constituent amount of the polymer block B is preferably 99 to 20% by mass, more preferably 97 to 40% by mass, and still more preferably 95 to 60% by mass with respect to the block copolymer. If the amount of the polymer block B is too small, the chain length of the polymer block B is short, so that a cross-linked polymer that is difficult to control between the cross-linking points is formed, and the tensile strength, fracture strength, and wear resistance are low. The same effect as when a general diene polymer is used, and the improvement effect may not be exhibited.

The block copolymer comprises at least two of the polymer blocks A and a polymer block B between these polymer blocks. When a plurality of polymer blocks B are provided, each polymer The blocks may be the same or different.
When each polymer block is different from each other, for example, when the structure or weight average molecular weight of each polymer block is different, the weight average molecular weight of each polymer block is the same, almost the same or adjacent to each other. The error range when the weight average molecular weights of the respective polymer blocks are compared is preferably in the range of ± 25%. The error range is more preferably ± 15%, still more preferably ± 10%. In other words, when there are a plurality of polymer blocks B, each polymer block may have the same structure or a different structure, but in any case, the weight average molecular weight of each polymer block is the same, or substantially the same, or The error range when the weight average molecular weights of adjacent polymer blocks are compared is preferably in the range of ± 25%. The error range is more preferably ± 15%, still more preferably ± 10%.

1-3. Structure of block copolymer The structure of the block copolymer is the same as that of the polymer block having the ethylenically unsaturated bond described above as “A ¹ ” and “A ² ” (where A ¹ and A ² may be the same or different. And when the other polymer block is “B”,
(1) A ¹ -B-A ²
(2) A ¹ -BA ² -BA ¹
(3) A ^1- (B-A ² ) _{n
^{(4) A 1 - (B}} -A 2) n - (B-A 1) m
(5) A ^1- (BA ² ) _n- (BA ¹ ) _m- (BA ² ) _m
(6) A ^1- (BA ² -BA ¹ ) _{n
^{(7) (A 1 -B)}} n X
(8) (A ¹ -BA ² ) _s X
(9) (A ¹ -BA ² -BA ¹ ) _s X
(10) (A ¹ -BA ¹ -BA ² ) _s X
(11) (A ¹ -BA ² -BA ² ) _s X
In the present invention, it is (8) in the case of a composition containing carbon black, and (2) in the case of a composition containing silica. However, m is an integer chosen from 1-4, n is an integer chosen from 2-6, s is an integer chosen from 1-6, and X is a residue of a coupling agent. It is. Moreover, in said (2)-(11), several B may be the same and may differ.

In the block copolymers represented by the structural formulas (7) to (11) above, the polymer block A ^{1 and the} like are alternately bonded to other polymer blocks B through the residue X of the coupling agent. It is a copolymer provided with extended or branched polymer molecular chains.
In addition, although the block copolymer represented by the structural formula of (8) is described as (A ¹ -B-A ² ) _s X for the sake of convenience, A ¹ , A ² and A ³ are different from each other. In the case where it is a block and s = 2, (A ¹ -BA ² ) -X- (A ¹ -BA ² ), (A ¹ -BA ² ) -X- (A ² -B-A ³ ), (A ¹ -BA ² ) -X- (A ¹ -BA ³ ), (A ¹ -BA ² ) -X- (A ³ -BA ² ) Etc. As described above, in the case of the structural formulas of other modes, it is possible to make various modes similarly.

When a plurality of polymer blocks B are included, as described above, each polymer block may be the same or different, but in the block copolymer represented by the structural formula (3) above, As a specific example in the case of having four polymer blocks B,
^{A-B 1 -A-B 1} -A-B 1 -A-B 1 -A
^{A-B 1 -A-B 1} -A-B 2 -A-B 2 -A
A-B ¹ -A-B ² -A-B ¹ -A-B ² -A
A-B ¹ -A-B ² -A-B ² -A-B ¹ -A
Etc.

Preferred combinations of the polymer blocks A and B constituting the block copolymer are as follows.
[I] The polymer block A uses 80% by mass or more of isoprene as a conjugated diene compound, and the polymer block B uses 1,3-butadiene as a conjugated diene compound (or isoprene and When 1,3-butadiene is used in combination, 80% by mass or more of 1,3-butadiene is used.)
[Ii] When 1,3-butadiene is used for the polymer blocks A and B, a polymer constituting a pre-hydrogenation polymer (a polymer including a polymer block that forms each polymer block) The block A ′ is a block mainly containing 1,4-bonds, and the polymer block B ′ constituting the polymer before hydrogenation is a block mainly containing 1,2-bonds is hydrogenated. What
[Iii] When isoprene is used for the polymer blocks A and B, the polymer block A ′ constituting the pre-hydrogenation polymer is a block mainly containing 1,4-bonds to constitute the pre-hydrogenation polymer. A product obtained by hydrogenating a polymer before hydrogenation in which the polymer block B ′ to be used is a block mainly containing 3,4-bonds, and the like.

The above embodiment will be described more specifically. Examples of [i] include a block copolymer using only isoprene in the polymer block A and only 1,3-butadiene in the polymer block B.
[Ii] is a block obtained by hydrogenating a polymer block A using 1,3-butadiene and containing a monomer unit mainly composed of 1,4-bonds. And a block containing a block obtained by hydrogenating a block containing a monomer unit, the polymer block B using 1,3-butadiene and mainly containing 1,2-bonds A copolymer etc. are mentioned.
In addition, as [iii], the polymer block A includes a block obtained by hydrogenating a block containing a monomer unit mainly composed of 1,4-bond, using isoprene. And the block copolymer containing the block obtained by hydrogenating with respect to the block which the polymer block B uses isoprene, and contains the monomer unit mainly having a 3, 4- bond, etc. are mentioned. It is done.

The composition ratio by each total amount of the polymer blocks A and B constituting the block copolymer according to the present invention is preferably 1 to 80% by mass / 99 to 20% by mass when the total of both is 100% by mass. %, More preferably 3 to 60% by mass / 97 to 40% by mass, and still more preferably 5 to 60% by mass / 95 to 40% by mass.

The weight average molecular weight of the block copolymer according to the present invention is preferably in the range of 7,000 to 1,000,000, preferably 25,000 to 900,000, more preferably 50,000 to 800,000. It is. If this weight average molecular weight is too small, the tensile strength, fracture strength and abrasion resistance of the crosslinked polymer may be lowered. On the other hand, if the weight average molecular weight is too large, workability is lowered, and as a result, tensile strength, fracture strength, and wear resistance may be lowered.

The ratio of the weight average molecular weight and the number average molecular weight (Mw / Mn) of the block copolymer according to the present invention is preferably in the range of 1 to 5, preferably 1 to 3, more preferably 1.1 to. 2.5. If this ratio is too large, both the low molecular weight component and the high molecular weight component are increased, so that the workability is lowered, and the tensile strength, fracture strength, and wear resistance of the crosslinked polymer may be lowered.

The block copolymer according to the present invention uses a polymer containing a polymer block that forms each of the polymer blocks (hereinafter, also referred to as “pre-hydrogenation polymer”). It is preferable to be obtained by performing a hydrogenation reaction on the coalescence. Further, the block copolymer according to the present invention is obtained by utilizing the ease of hydrogenation of each polymer block constituting the pre-hydrogenation polymer, that is, utilizing the difference in hydrogenation rate. Is preferred.
Accordingly, the polymer block A constitutes a pre-hydrogenation polymer, and the hydrogenation rate for the polymer block A ′ that forms the polymer block A by the hydrogenation reaction is significantly reduced. It is a polymer block obtained by making the addition reaction difficult to proceed or by preventing it from proceeding. That is, in the polymer block A, 80% or more of the unsaturated bonds derived from the conjugated diene compound and the like contained in the polymer block A ′ are not hydrogenated and remain as ethylenically unsaturated bonds. More preferably 85% or more, still more preferably 90% or more, and particularly preferably 95% is not hydrogenated.
Further, the polymer block B constitutes a pre-hydrogenation polymer and significantly increases the rate of hydrogenation with respect to the polymer block B ′ which forms the polymer block B by a hydrogenation reaction. It is the obtained polymer block. That is, in the polymer block B, 80% or more of unsaturated bonds derived from the conjugated diene compound and the like contained in the polymer block B ′ are hydrogenated. More preferably, it is 85% or more, further preferably 88 to 99%, particularly preferably 90 to 98%.

1-4. Process for Producing Block Copolymer Also, the block copolymer comprises a step [I] of polymerizing a monomer (t1) containing a conjugated diene compound and a conjugated diene in the presence of the obtained polymer (P1). A step [II] of polymerizing a monomer (t2) containing a compound, a step [III] of polymerizing a monomer (t3) containing a conjugated diene compound in the presence of the obtained polymer (P2), and The hydrogenation rate in the polymer block obtained in the steps [I] and [III] obtained by hydrogenating the polymer (P3) obtained by providing The hydrogenation rate in the polymer block formed in the above step [II] may be 80 to 100%. However, when each of these three steps is performed once, the block copolymer having the structure of the aspect (1) described in the above section 1-3, that is, the structure of A ¹ -B-A ² and To obtain a polymer A ¹ '-B'-A ² ' before hydrogenation. When the block copolymer having another structure such as the embodiments (2) to (6) described in the above section 1-3 is used, the polymerization corresponding to the steps [II] and [III] is further repeated. Just do it.

  In step [I], the monomer (t1) containing a conjugated diene compound is polymerized. This conjugated diene compound can be used in combination with an aromatic vinyl compound or the like, if necessary. This step [I] is carried out to form the polymer block A, and examples and use amounts of these compounds are as described in the above section 1-1. The polymerization in this step [I] is preferably anionic polymerization using an organolithium compound as a polymerization initiator.

Examples of the organic lithium compound include a hydrocarbon compound of metallic lithium, a complex of metallic lithium and a polar compound, and the like. Examples of metallic lithium hydrocarbon compounds include ethyl lithium, n-propyl lithium, i-propyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, n-octyl lithium, and n-decyl. Examples thereof include lithium, phenyl lithium, 2-butyl-phenyl lithium, 2-naphthyl lithium, cyclohexyl lithium, 4-cyclopentyl lithium and the like. These can be used alone or in combination of two or more.
The organolithium compounds can be used in combination with phenoxides containing alkaline earth metals such as barium nonylphenoxide, organoaluminum compounds such as trialkylaluminum, alkali metal salts of dialkylaminoethanol, alkali metal salts of monoalkylene glycol, and the like. .

  As the solvent used for the polymerization, hydrocarbons such as aliphatic hydrocarbons, aromatic hydrocarbons and alicyclic hydrocarbons can be usually used. Examples of the aliphatic hydrocarbon include n-pentane, i-pentane, n-hexane, n-heptane, and n-octane. Aromatic hydrocarbons include benzene, xylene, ethylbenzene and the like. Examples of alicyclic hydrocarbons include methylcyclopentane and cyclohexane. These can be used alone or in combination of two or more.

The polymerization in the step [I] is usually performed in a range of 0 to 120 ° C. by a batch polymerization method or a continuous polymerization method, and may be performed at a constant temperature or may be performed while raising the temperature. The polymerization time is usually in the range of 5 minutes to 12 hours.
A polymer (P1) is obtained by said process [I]. The polymer (P1) corresponds to the polymer block A ¹ ′ (before hydrogenation) for making the structure A ¹ ′ -B′-A ² ′ of the polymer before hydrogenation.
The weight average molecular weight of the polymer (P1) obtained by the above step [I] is preferably in the range of 1,000 to 20,000, more preferably 3,000 to 18,000, still more preferably 5,000. ~ 15,000.

  In step [II], the monomer (t2) containing a conjugated diene compound is polymerized in the presence of the polymer (P1). This conjugated diene compound is used in combination with an aromatic vinyl compound or the like. This step [II] is carried out to form the polymer block B, and examples and amounts used of these compounds are as described in the above section 1-2. Moreover, it is preferable to perform superposition | polymerization in this process [II] on the conditions similar to the said process [I]. In addition, in this process [II], you may advance by adding a monomer (t2) etc. using the polymerization system in the said process [I].

The polymerization in the step [II] is usually performed in a range of 0 to 120 ° C. by a batch polymerization method or a continuous polymerization method, and may be performed at a constant temperature or may be performed while raising the temperature. The polymerization time is usually in the range of 5 minutes to 12 hours.
The polymer (P2) is obtained by the step [II]. The polymer (P2) includes a portion corresponding to the polymer block B ′ (before hydrogenation) for making the structure A ¹ ′ -B′-A ² ′ of the polymer before hydrogenation.
In addition, the weight average molecular weight of the polymer block B ′ according to the above step [II] is 5,000 to 121,000 or 5,000 to 100,000, and in the latter case, more preferably 20,000 to 95,000. More preferably, it is 35,000-85,000.

  In step [III], the monomer (t3) containing a conjugated diene compound is polymerized in the presence of the polymer (P2). This conjugated diene compound can be used in combination with an aromatic vinyl compound or the like, if necessary. This step [III] is carried out to form the polymer block A, and examples and amounts used of these compounds are as described in the above section 1-1. Moreover, it is preferable to perform superposition | polymerization in this process [III] on the conditions similar to the said process [I] or [II]. In addition, in this process [III], you may advance by adding a monomer (t3) etc. using the polymerization system in the said process [II].

The polymerization in the step [III] is usually performed in the range of 0 to 120 ° C. by a batch polymerization method or a continuous polymerization method, and may be performed at a constant temperature or may be performed while raising the temperature. The polymerization time is usually in the range of 5 minutes to 12 hours.
A polymer (P3) is obtained by the said process [III]. This polymer (P3) includes a portion corresponding to the polymer block A ² ′ (before hydrogenation) in the structure A ¹ ′ -B′-A ² ′ of the polymer before hydrogenation.
The weight average molecular weight of the polymer block A ² ′ by the above step [III] is preferably in the range of 1,000 to 20,000, more preferably 3,000 to 18,000, still more preferably 5, 000 to 15,000.

  In the above steps [I], [II] and [III], a conjugated diene compound and an aromatic vinyl compound are used in combination, and monomer units comprising the aromatic vinyl compound are randomly arranged in the polymer block. Alternatively, when a single chain is formed by the monomer units, an ether compound, a tertiary amine compound, a potassium compound, or the like can be added to the reaction system for polymerization. Moreover, when the following compound etc. are used, the microstructure (vinyl bond content) in the polymerization part of a conjugated diene compound can also be adjusted.

  Examples of the ether compound include tetrahydrofuran, α-methoxytetrahydrofuran, dimethoxybenzene, dimethoxyethane, diethyl ether, di-n-butyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, bistetrahydrofurylpropane, and the like. Can be mentioned. These can be used alone or in combination of two or more.

  Examples of the tertiary amine compound include triethylamine, pyridine, N, N, N ′, N′-tetramethylethylenediamine, 1,2-dipiperidinoethane, N-methylmorpholine, and the like. These can be used alone or in combination of two or more.

  Examples of the potassium compound include potassium alkoxide, potassium phenoxide, potassium benzyl oxide, fatty acid potassium salt, aromatic carboxylic acid potassium salt, organic sulfonic acid potassium salt, and organic phosphorous acid potassium salt. These can be used alone or in combination of two or more.

Examples of potassium alkoxide include potassium isopropoxide, potassium tert-butoxide, potassium tert-amyloxide, potassium n-heptaoxide, and other general formulas RCH ₂ OK (where R is a hydrogen atom or carbon atom having 1 to 10 carbon atoms). It is a hydrogen group).
Examples of the potassium salt of fatty acid include potassium salts such as 2-ethylhexanoic acid, isovaleric acid, caprylic acid, lauric acid, palmitic acid, stearic acid, oleic acid, and linolenic acid.
Examples of the potassium salt of aromatic carboxylic acid include potassium salts such as benzoic acid and phthalic acid.

Examples of the potassium salt of organic sulfonic acid include potassium salts such as dodecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, and octadecylbenzenesulfonic acid.
Examples of the potassium salt of organic phosphorous acid include potassium salts such as diethyl phosphite, diisopropyl phosphite, dibutyl phosphite, dilauryl phosphite, and diphenyl phosphite.

The amount of the potassium compound used is preferably 0.005 to 0.5 mol per gram of atomic equivalent of lithium in the organolithium compound used to make the lithium polyfunctional polymerization initiator. If the amount of the potassium compound used is less than 0.005 mol, the addition effect (reactivity improvement by lithium-based polyfunctional polymerization initiator, randomization of aromatic vinyl compound or single chain impartation) may not be sufficient, On the other hand, when the amount exceeds 0.5 mol, the polymerization activity is lowered, the productivity is greatly lowered, and the modification efficiency at the time of performing the reaction of modifying the polymer terminal with a functional group may be lowered. .
In addition, although the usage method in the case of using the said potassium compound is not specifically limited, It is preferable to use together with a polymerization initiator.

Furthermore, with respect to the active terminal of the polymer obtained in each step of the above steps [I] to [III], ethylene oxide, carbon dioxide gas, dialkylaminobenzaldehyde, benzophenone, 4,4′-dialkylaminobenzzophenone, N - methyl oxazolidinone, tolylene diisocyanate, diphenylmethane diisocyanate, carbon disulfide, tetraalkoxysilane, by stopping with a compound such as an alkyl triphenoxy silane, -OH group, -COOH group, -NR ₂ group, -NHR group, -NCO group, -CSH group, -Si (OR) _n group and the like (R is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and n is 1 to 3 Which is an integer).

  In addition, by repeating the above steps [I] to [III] as appropriate, the hydrogenation of the block copolymer having the structure such as the embodiments (2) to (6) described in the above section 1-3 is performed. The prepolymer can be easily obtained. In that case, you may change the kind and usage-amount of the monomer used in each process according to the objective and a use. However, in order to make the interval between the polymer blocks A ′ constant, that is, to make the weight average molecular weight of the polymer block B ′ constant at a predetermined value, for example, the mode (2) described in the above section 1-3 When the block copolymer having the structure of (6) or the like is used, the same polymer block B ′ is formed under the same conditions of the step [II] to be repeated, or the weight average molecular weight is first It is preferable to proceed the polymerization under conditions for forming different types of polymer blocks B ′ so as to be equivalent to B ′ formed in the above.

A block copolymer can be obtained by hydrogenating the polymer (P3) obtained by providing the steps [I] to [III].
The method of hydrogenation is not particularly limited, and any method and conditions can be applied as long as the hydrogenation rate with respect to each polymer block constituting the pre-hydrogenation polymer can be a predetermined one. . Usually, a hydrogenation reaction is performed on a pre-hydrogenated polymer in the presence of a catalyst in a hydrogen gas atmosphere at a predetermined pressure under a temperature condition in the range of 0 to 150 ° C.

  Examples of the catalyst include (i) a catalyst in which a metal such as nickel, palladium, platinum, rhodium, ruthenium, and rhenium is supported on a carrier such as carbon, silica, alumina, and diatomaceous earth, and (ii) a phosphorus compound is coordinated. (Iii) an organic compound or organometallic compound containing titanium element (titanium tetrachloride, titanocene dichloride, titanocene diphenyl, titanocene ditolyl, titanocene dibenzyl, etc.), (iv) iron, Organic compounds containing transition metal elements such as nickel, cobalt and zirconium (zirconocene dichloride, iron trisacetylacetonate, cobalt trisacetylacetonate, cobalt octoate, cobalt naphthenate, nickel bisacetylacetonate, nickel octoate, naphthenic acid Nickel etc.) , Organolithium of group 1 to 3 of the periodic table, polymer lithium, alkyl magnesium compound (dialkyl magnesium, Grignard reagent, etc.), alkyl aluminum compound (trialkyl aluminum, dialkyl aluminum chloride, dialkyl aluminum hydride, etc.), alkyl zinc compound, etc. And a catalyst comprising an organometallic compound selected from: Among these, (iii) organic compounds or organometallic compounds containing titanium element (titanium tetrachloride, titanocene dichloride, titanocene diphenyl, titanocene ditolyl, titanocene dibenzyl, etc.) are preferable.

The hydrogen reaction using the catalyst is usually performed in the range of 0 to 150 ° C. The pressure of hydrogen gas is performed in the range of 1 to 100 kgf / cm ² . The reaction time is usually in the range of 5 minutes to 24 hours.

By performing hydrogenation under the above-described conditions on the pre-hydrogenation polymer (P3) obtained by the above-described steps, the rate of hydrogenation for each polymer block constituting the pre-hydrogenation polymer (P3) is different. Can be. That is, the hydrogenation rate for the polymer blocks A ¹ ′ and A ² ′ formed in the steps [I] and [III] is less than 20%, preferably 0 to 10%, more preferably 0 to 5%. The hydrogenation rate with respect to the polymer block B ′ formed in the step [II] is 80 to 100%, preferably 85 to 100%, more preferably 90 to 98%. be able to.

In addition, the block copolymer includes a step [I] of polymerizing a monomer (t1) containing a conjugated diene compound, and a monomer containing a conjugated diene compound in the presence of the obtained polymer (P1) ( a polymer (P5) obtained by providing a step [II] for polymerizing t2) and a step [IV] for coupling the obtained polymer (P4) using a polyfunctional coupling agent. Is a block copolymer obtained by hydrogenation, the hydrogenation rate in the polymer block formed in the step [I] is less than 20%, and formed in the step [II]. The hydrogenation rate in the polymer block may be 80 to 100%. By providing the steps [I], [II] and [IV], the block copolymer having the structure of the aspect (7) described in the above section 1-3, that is, the structure of (A ¹ -B) _n X To obtain a polymer (A ¹ '-B') _n X before hydrogenation.

Steps [I] and [II] can be the same as described above. In order to obtain the pre-hydrogenation polymer (A ¹ ′ -B ′) _n X, the steps [I] and [II] are alternately performed at least twice. When each of the above steps [I] and [II] is repeated twice or more, the type and amount of monomer used in each step may be changed according to the purpose and application.

  In step [IV], the polymer (P4) is subjected to coupling using a polyfunctional coupling agent. Examples of this multifunctional coupling agent include silicon tetrachloride, methyl silicon trichloride, dimethyldichlorosilicon, trimethylchlorosilicon, silicon halide compounds such as silicon tetrabromide, and alkoxysilicons such as tetraethoxysilicon and tetraphenoxysilicon. Compounds, tin halide compounds such as tin tetrachloride, methyltin trichloride, dibutyldichlorotin, tributylchlorotin, allyltin compounds such as tetraallyltin, diethyldiallyltin, tetra (2-octenyl) tin, tetraphenyltin, tetra Aromatic tin compounds such as benzyltin, germanium halides such as germanium tetrachloride, diethyl adipate, 1,2-dibromoethane, divinylbenzene, 1,4-chloromethylbenzene and the like can be mentioned. These coupling agents can be used alone or in combination of two or more.

  The coupling in the step [IV] is usually performed in the range of 0 to 120 ° C., may be performed at a constant temperature, or may be performed while raising the temperature. The reaction time is usually in the range of 1 minute to 2 hours.

By performing hydrogenation in the same manner as described above on the polymer (P5) obtained by providing the above steps [I], [II] and [IV], the embodiment described in the above section 1-3 ( A block copolymer having the structure 7) can be obtained. In this hydrogenation, the hydrogenation rate for the respective polymer blocks constituting the pre-hydrogenation polymer (P5) is different by performing hydrogenation under the above conditions on the pre-hydrogenation polymer (P5). can do. That is, the hydrogenation rate to the polymer block A ¹ ′ formed in the above step [I] is less than 20%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0%, and The hydrogenation rate for the polymer block B ′ formed in the step [II] can be 80 to 100%, preferably 85 to 100%, more preferably 90 to 98%.

In addition, the block copolymer includes a step [I] of polymerizing a monomer (t1) containing a conjugated diene compound, and a monomer containing a conjugated diene compound in the presence of the obtained polymer (P1) ( a step [II] of polymerizing t2), a step [III] of polymerizing a monomer (t3) containing a conjugated diene compound in the presence of the obtained polymer (P2), and a polymer ( A block copolymer obtained by hydrogenating the polymer (P6) obtained by comprising the step [V] of coupling P3) using a polyfunctional coupling agent, The hydrogenation rate in the polymer block formed in the steps [I] and [III] is less than 20%, respectively, and the hydrogenation rate in the polymer block formed in the step [II] is 80 to 100%. Can be . By providing the steps [I], [II], [III] and [V], a block copolymer having a structure such as the aspects (8) to (11) described in the above section 1-3 is obtained. Polymers before hydrogenation, for example, (A ¹ ′ -B′-A ² ′) _s X, (A ¹ ′ -B′-A ² ′ -B′-A ¹ ′) _s X, (A ¹ ′ − B′-A ¹ ′ -B′-A ² ′) _s X, (A ¹ ′ -B′-A ² ′ -B′-A ² ′) _s X, etc. are obtained.

  Steps [I], [II] and [III] can be the same as described above. Further, the above steps [I] to [III] may be repeated as appropriate. In that case, you may change the kind and usage-amount of the monomer used in each process according to the objective and a use. However, in order to make the interval between the polymer blocks A ′ constant, that is, to make the weight average molecular weight of the polymer block B ′ constant at a predetermined value, the conditions of the process [II] to be repeated are the same and the same It is preferable to carry out the polymerization under the condition that the polymer block B ′ is formed, or the polymer block B ′ of a different type is formed so that the weight average molecular weight is equal to that of the initially formed B ′.

The coupling in the step [V] can be the same as in the above step [IV]. The polymer (P6) obtained by providing the above steps [I], [II], [III] and [V] is hydrogenated in the same manner as described above to obtain the above 1-3. The block copolymer which has structures, such as aspect (8)-(11) demonstrated by the term, can be obtained. In this hydrogenation, the hydrogenation rate for each polymer block constituting the pre-hydrogenation polymer (P6) is different by performing hydrogenation under the above conditions on the pre-hydrogenation polymer (P6). can do. That is, the hydrogenation ratio to the polymer block A ¹ ′ formed in the steps [I] and [III] is less than 20%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0%. In addition, the hydrogenation rate of the polymer block B ′ formed in the step [II] can be 80 to 100%, preferably 85 to 100%, more preferably 90 to 98%.

In each of the above embodiments, after the hydrogenation reaction, a step of removing the catalyst residue from the polymerization solution, a step of adding a phenol-based or amine-based anti-aging agent, etc., acetone, alcohol, etc. are added to the polymerization solution. The block copolymer can be easily isolated by a method of precipitation by addition, a method of pouring the polymerization solution into hot water under stirring, and a method of distilling off the solvent.
The weight average molecular weight of the obtained block copolymer is preferably in the range of 7,000 to 1,000,000, preferably 25,000 to 900,000, more preferably 50,000 to 800,000. is there. The ratio of the weight average molecular weight and the number average molecular weight (Mw / Mn) is preferably in the range of 1 to 5, preferably 1 to 3, more preferably 1.1 to 2.5.

In the above description, polymer blocks A ′ and B ′ are alternately formed to produce a pre-hydrogenation polymer, and then a hydrogenation reaction is performed to obtain a block copolymer.
As another production method, for example, a block copolymer having the structure of the aspect (1) described in the above section 1-3 will be described. First, the polymer B ′ is produced first, and then the polymer block A ′ is added at a time to obtain a pre-hydrogenation polymer, and then a hydrogenation reaction is performed to obtain a block copolymer. . In this case, the two polymer blocks A ′ formed are the same. In forming the polymer block A ′, it is preferable to polymerize the predetermined monomer (t1) in the presence of a polar compound. Examples of polar compounds include diethyl ether, di-n-butyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, tetrahydrofuran, and 2,2- (bis Ether compounds such as tetrahydrofurfuryl) propane, bistetrahydrofurfuryl formal, methyl ether of tetrahydrofurfuryl alcohol, ethyl ether of tetrahydrofurfuryl alcohol, butyl ether of tetrahydrofurfuryl alcohol, α-methoxytetrahydrofuran, dimethoxybenzene, dimethoxyethane; Triethylamine, pyridine, N, , N ′, N′-tetramethylethylenediamine, dipiperidinoethane, methyl ether of N, N-diethylethanolamine, ethyl ether of N, N-diethylethanolamine, butyl ether of N, N-diethylethanolamine, etc. And tertiary amine compounds. These can be used alone or in combination of two or more.

Since the block copolymer having the structure according to the aspect (2) or (8) according to the present invention is excellent in the regularity of the structure, the block copolymer is excellent in processability when used as a rubber composition. Furthermore, when crosslinked, the crosslinked polymer forms a regular network structure by crosslinking using the ethylenically unsaturated bond of the polymer block A. It can be set as the crosslinked rubber composition excellent in abrasion property, ozone resistance, and heat aging resistance. This crosslinked rubber composition contains various additives described later, for example, fillers such as silica, softeners such as process oil, anti-aging agents, processing aids, etc., which are blended in rubber products. Even if it exists, it has the property which has these compounding effects together.

The crosslinking agent used for the formation of the crosslinked polymer is not particularly limited, and can form a crosslinked bond using an ethylenically unsaturated bond contained in the polymer block A constituting the block copolymer, or In the case of containing a monomer unit composed of an aromatic vinyl compound, those capable of reacting at least with an alkyl group bonded to an aromatic ring to form a cross-linked bond are preferred. Sulfur, a sulfur-containing compound, an organic peroxide Etc.

  Examples of sulfur include powdered sulfur, surface-treated sulfur, insoluble sulfur, precipitated sulfur, colloidal sulfur and the like. Examples of the sulfur-containing compound include (poly) sulfide compounds.

  Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5. -Di- (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane N-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxide Oxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxy De, etc. tert- butyl cumyl peroxide. These can be used alone or in combination of two or more.

In addition, when using sulfur among the said crosslinking agents, a vulcanization accelerator, a vulcanization adjuvant, etc. can be used together.
Examples of the vulcanization accelerator include thiuram, dithiocarbamate, xanthate, guanidine, aldehyde-amine, aldehyde-ammonia, thiazole, sulfenamide, and thiourea compounds.
Thiuram-based vulcanization accelerators include tetrakis (2-ethylhexyl) thiuram disulfide (TOT-N), tetramethylthiuram monosulfide (TS), tetraethylthiuram disulfide (TET), tetramethylthiuram disulfide (TT), dipentamethylene. Examples include thiuram hexasulfide (TRA). These can be used alone or in combination of two or more.
Examples of the vulcanization aid include higher fatty acids such as zinc oxide and stearic acid.

  Since the cross-linked polymer obtained by mixing the block copolymer and the cross-linking agent preferably under heating in the range of room temperature to 220 ° C. forms a regular network structure, various physical properties, For example, it is suitable as a molded article excellent in wear resistance, ozone resistance and heat aging resistance.

2 . Rubber composition The rubber composition of the present invention comprises the above block copolymer and a filler of carbon black or silica.

  Examples of carbon black include furnace black, acetylene black, thermal black, channel black, and graphite. These carbon blacks can be used singly or in combination of two or more. Of these carbon blacks, furnace black is preferable, and specific examples thereof include SAF, ISAF, ISAF-HS, ISAF-LS, IISAF-HS, HAF, HAF-HS, HAF-LS, MAF, FEF, and FEF-. Examples include various grades such as LS, GPF, GPF-HS, GPF-LS, SRF, SRF-HS, and SRF-LM. These can be used alone or in combination of two or more.

Nitrogen adsorption specific surface area _(N 2 SA) of carbon black is not particularly limited, usually from 5 to 200 m ² / g, preferably from 10 to 150 m ² / g, more preferably 20~130m ² / g. If the nitrogen adsorption specific surface area is in the above range, the crosslinked rubber composition is particularly excellent in tensile strength, abrasion resistance and the like.
The DBP adsorption amount of carbon black is not particularly limited, but is usually 5 to 300 ml / 100 g, preferably 20 to 200 ml / 100 g, more preferably 50 to 160 ml / 100 g. When the DBP adsorption amount is in the above range, the crosslinked rubber composition is particularly excellent in tensile strength, wear resistance, and the like.

Examples of silica include dry method white carbon, wet method white carbon, colloidal silica, and precipitated silica. These silicas can be used alone or in combination of two or more. Of these, wet method white carbon mainly containing hydrous silicic acid is preferred.
Although the specific surface area of silica is not particularly limited, a nitrogen absorption specific surface area, typically, 50 to 400 m ² / g, preferably 100 to 250 m ² / g, more preferably from 120~220m ² / g. If the nitrogen adsorption specific surface area is in the above range, the crosslinked rubber composition is particularly excellent in tensile strength, abrasion resistance and the like. Here, the nitrogen adsorption specific surface area is a value measured by the BET method according to ASTM D3037-81.

The above carbon black and silica can be used alone or in combination.
When only carbon black is used as the filler, the content of the carbon black is preferably 20 to 120 parts by mass, more preferably 30 to 100 parts by mass, and still more preferably 40 to 100 parts by mass of the block copolymer. It is -90 mass parts. When the content of carbon black exceeds 120 parts by mass, when excessive carbon black becomes a breaking point and the tensile strength decreases, the wear resistance may decrease with an increase in hysteresis loss.

When only silica is used as the filler, the content of silica is preferably 20 to 140 parts by mass, more preferably 30 to 120 parts by mass, and still more preferably 40 to 100 parts per 100 parts by mass of the block copolymer. Part by mass. When the content of silica exceeds 140 parts by mass, when excessive silica becomes a breaking point and the tensile strength decreases, the wear resistance may decrease as the hysteresis loss increases.
In addition, carbon black and silica may be used in combination as a filler. In this case, the total content of carbon black and silica is preferably 20 to 140 parts by mass with respect to 100 parts by mass of the block copolymer, More preferably, it is 30-120 mass parts, More preferably, it is 40-100 mass parts. The ratio of carbon black and silica at this time is preferably 5 to 95% by mass / 95 to 5% by mass, more preferably 10 to 90% by mass / 90 to 10% by mass, when the total of both is 100% by mass. It is.

The rubber composition of the present invention includes, in addition to the above filler, aluminum hydroxide [Al (OH) ₃ ] such as alumina monohydrate (Al ₂ O ₃ .H ₂ O), gibbsite, bayerite, water, etc. magnesium oxide [Mg _(OH) 2], magnesium oxide (MgO), talc _{(3MgO · 4SiO 2 · H 2} O), attapulgite _{(5MgO · 8SiO 2 · 9H 2} O), titanium dioxide _(TiO 2), titanium black ( TiO _2n-1 ), calcium oxide (CaO), calcium hydroxide [Ca (OH) ₂ ], aluminum magnesium oxide (MgO · Al ₂ O ₃ ), clay (Al ₂ O ₃ · 2SiO ₂ ), kaolin (Al _{2 O 3 · 2SiO 2 · 2H 2} O), pyrophyllite _{(Al 2 O 3 · 4SiO 2} · H 2 O), bentonite _(Al 2 O _{· 4SiO 2 · 2H 2 O)} , aluminum silicate _{(Al 2 SiO 5, Al 4} · 3SiO 4 · 5H 2 O etc.), magnesium silicate _{(Mg 2} SiO 4, MgSiO ₃ etc.), calcium silicate (Ca ₂ SiO ₄ etc.), aluminum calcium silicate (Al ₂ O ₃ · CaO · 2SiO ₂ etc.), magnesium calcium silicate (CaMgSiO ₄ ), inorganic fillers such as carbon black · silica · dual phase filler, polymer filler, etc. The organic filler may be contained.

  The rubber composition of the present invention further comprises a softening agent, a crosslinking agent containing a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, a silane coupling agent, an anti-aging agent, a plasticizer, a tackifier, and a heat stabilizer. Further, it may contain various additives such as a light stabilizer, an ultraviolet absorber, a colorant, an antistatic agent, a lubricant and a flame retardant, and other polymers.

Softeners include process oil, paraffin, liquid paraffin, petroleum asphalt, petroleum jelly and other mineral oils; castor oil, linseed oil, rapeseed oil, soybean oil, coconut oil and other vegetable oils; tall oil, beeswax, carnauba wax, lanolin, etc. Waxes; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, and calcium stearate or metal salts thereof; ester compounds such as dioctyl phthalate, dioctyl adipate, and dioctyl sebacate. These can be used alone or in combination of two or more.
The blending amount of the softening agent is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, and still more preferably 50 parts by mass or less, with respect to 100 parts by mass of the total of the polymer components including the block copolymer. .

As the crosslinking agent, those exemplified above can be used, and the blending amount thereof is preferably 0.1 to 15 parts by mass, more preferably 100 parts by mass with respect to a total of 100 parts by mass of the polymer components including the block copolymer. It is 0.3-10 mass parts, More preferably, it is 0.5-5 mass parts.
As the vulcanization accelerator, those exemplified above can be used, and the blending amount thereof is preferably 0.1 to 15 parts by mass with respect to 100 parts by mass in total of the polymer components including the block copolymer. Preferably it is 0.3-10 mass parts, More preferably, it is 1-10 mass parts.

The silane coupling agent can improve the wear resistance and the like of the resulting vulcanized rubber composition by blending when silica is used as the filler. Examples include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxy-ethoxy) silane, β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyl Tomethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, bis- [3- (triethoxysilyl) ) Propyl] tetrasulfur I, bis - [3- (triethoxysilyl) propyl] disulfide, .gamma.-trimethoxysilylpropyl dimethylthiocarbamoyl tetrasulfide, .gamma.-trimethoxysilylpropyl benzothiazyl tetrasulfide and the like. These can be used alone or in combination of two or more.
The amount of the silane coupling agent is preferably 1 to 20 parts by mass, particularly preferably 2 to 15 parts by mass, when silica is 100 parts by mass.

Examples of the antiaging agent include amines and phenols.
Examples of the plasticizer include phosphate esters such as tributyl phosphate, acid esters such as dibutyl phthalate, butyl oleate, and dibutyl adipate, and chlorinated paraffins.

The rubber composition of the present invention can be produced, for example, as follows.
First, a polymer component containing the block copolymer, a filler, and an additive such as a softening agent are kneaded usually at a temperature of 70 to 180 ° C. using a kneader such as a Banbury mixer. Thereafter, the kneaded product is cooled. Next, a rubber composition is obtained by adding a crosslinking agent such as sulfur, a vulcanization accelerator, and the like, and further kneading.
When the rubber composition of the present invention is a vulcanized rubber composition, it is excellent in tensile properties, abrasion resistance, ozone resistance and heat aging resistance.

4). Molded Article The molded article of the present invention is obtained by using the rubber composition. That is, the molded article of the present invention contains at least the above crosslinked polymer.
The molded article of the present invention can be obtained, for example, by introducing the rubber composition into a mold having a predetermined shape. The method of crosslinking is selected according to the crosslinking agent contained.

The molded article of the present invention is composed of a vulcanized rubber composition, and the tensile strength measured according to JIS K6301 is preferably 20 MPa or more, more preferably 25 MPa or more, and further preferably 30 MPa or more. it can.
Also, the Lambourne wear index according to the experimental method described below is preferably 1. compared to the case of using a butadiene / isoprene / styrene copolymer (Mw = 11.5 thousand, Mw / Mn = 1.15) by batch polymerization. 5 times or more, more preferably 1.6 times or more, and still more preferably 1.7 times or more.

  Examples of the molded article of the present invention include rubber products for tires such as treads, sidewalls, and carcass, anti-vibration rubber, various belts, various rollers, and various sealing materials.

  Hereinafter, the present invention will be specifically described with reference to examples. In addition, this invention is not restrict | limited at all by these Examples. Further, “%” and “part” in the examples are based on mass unless otherwise specified.

Various measurement items and measurement methods are as follows.
(1) it was determined by comparison of ^{1 H-NMR} of the ethylenically unsaturated bond content of hydrogenated before or after the polymer.
(2) Weight average molecular weight (Mw) and number average molecular weight (Mn)
It calculated | required in polystyrene conversion using the gel permeation chromatography (GPC) apparatus (model "244 type | mold", the Waters company make).
(3) Workability A set of dump rubber after kneading and the gloss of the surface of the test piece were visually inspected and evaluated according to the following criteria. “◎” means that the rubber is well-organized and surface gloss is very good, “○” is good, “△” is a little bad, and “×” means that the dump rubber is not loose and there is no gloss on the rubber surface. Indicates a state.
(4) Tensile strength Measured according to JIS K6301.
(5) Lambourn Wear Index Using a Lambourn wear tester, the amount of wear when the slip rate at 50 ° C. was 60% was measured.

(6) The ozone resistance measurement condition is that the ozone concentration is 50 ppm, the elongation is 20%, the measurement temperature is 50 ° C., the surface of each test piece after 5 hours, 25 hours, and 50 hours by visual inspection, Evaluation was made according to the following criteria.
[Number of cracks] A; None
B: Several
C;
D: Many
E: Innumerable [crack size] 1; None
2; finally visible to the naked eye
3; Visible to the naked eye
4; Small crack (1mm or less)
5; Medium crack (1-3mm)
6; Coarse crack (more than 3mm)
For example, when there are several cracks that are finally visible to the naked eye, “B-2” is displayed as the evaluation result.
(7) Heat aging resistance The heat aging resistance was measured by measuring the tensile strength and elongation after the test piece was left in a gear oven at 100 ° C. for 48 hours, and the change in the value measured before being put into the gear oven. Showed the rate. The tensile strength was measured according to JIS K6301.

1. Production of block copolymers
Reference Example 1-1
An autoclave having an internal volume of 5 liters was charged with 2,400 g of degassed and dehydrated cyclohexane, 12.0 g of tetrahydrofuran (THF), and 31 g of isoprene, and then 0.5 g (7.81 mmol) of n-butyllithium (nBuLi). Was added, and the temperature rising polymerization from 40 ° C to 50 ° C was carried out. After confirming that the polymerization conversion rate was 100%, 265 g of 1,3-butadiene and 88 g of styrene were added, and a temperature rising polymerization from 50 ° C. to 80 ° C. was performed. Further, after confirming a polymerization conversion rate of 100%, 16 g of isoprene was added, and polymerization was carried out at 80 to 85 ° C. for 15 minutes. Thereafter, 0.315 g (1.85 mmol) of silicon tetrachloride was added as a coupling agent, and a coupling reaction was carried out for 15 minutes to obtain a polymerization solution containing a block copolymer before hydrogenation.
On the other hand, 1.95 g of titanocene dichloride was dispersed in 30 ml of cyclohexane using another container, and 2.68 g of triethylaluminum was added and reacted at room temperature. Thereafter, the apparently dark blue apparently uniform solution was added to and mixed with the polymerization solution obtained above, and the hydrogenation reaction was carried out at 50 ° C. under a hydrogen gas pressure of 5.0 kgf / cm ² for 2 hours. It was. Next, the polymer and the solvent are separated using a methanol / hydrochloric acid solution, and then 3.5 g of 2,6-di-tert-butylcatechol is added and dried under reduced pressure, whereby a partially hydrogenated block copolymer is obtained. Combined (a) was obtained. The structure of this block copolymer is (A ¹ -B ¹ -A ² ) ₄ X type, and the hydrogenation rate for the polymer block A ¹ ′ formed by the first stage polymerization is 0%, the second stage The hydrogenation rate for the polymer block B ¹ ′ formed by the polymerization was 99%, and the hydrogenation rate for the polymer block A ² ′ formed by the third stage polymerization was 0%. Further, the weight average molecular weight was 357,000, Mw / Mn was 1.35, and each constituent amount of the polymer blocks A and B, each weight average molecular weight, and each ethylenically unsaturated bond content are shown in Table 1. It was shown to.

Reference Examples 1-2 to 1-9
Tables 1 and 2 show the types and amounts of monomer compounds used to obtain the block copolymer before hydrogenation, the amounts of nBuLi used, the amounts of THF used, and the types and amounts of coupling agents used. Except that the amount of the copolymer was changed as shown in Table 1, the polymerization reaction and the hydrogenation reaction were performed in the same manner as in Reference Example 1-1 to obtain block copolymers (b) to (i). Table 1 and Table 2 show the structure and weight average molecular weight, the constituent amounts of the polymer blocks A and B, and the weight average molecular weight and the content of each ethylenically unsaturated bond for each of the obtained block copolymers. Also written.

In addition, the block copolymer (b) of Reference Example 1-2 is obtained by using 1/10 of the amount of THF used in Reference Example 1-1, and the diene unit of each polymer block. The microstructure of is changed.
In addition, the block copolymer (i) of Reference Example 1-9 is a polymer block A ¹ ′ formed by the first-stage polymerization is a polymer block having a small amount of 1,2-bonds, and the second-stage polymerization. Is selectively hydrogenated in the 1,2-bond part of the linear molecular chain of the block copolymer before hydrogenation, in which the polymer block B ¹ ′ formed by the above process is a polymer block having a large amount of 1,2-bonds It was obtained.

Reference Example 1-10
In the same manner as in Reference Example 1-5, a (A ¹ -B ¹ ) ₂ X-type linear polymer was synthesized, and a block copolymer that was not subjected to a hydrogenation reaction was prepared as a block copolymer (j). did. With respect to the obtained block copolymer (j), the structure and weight average molecular weight, the constituent amounts of the polymer blocks A and B, and the weight average molecular weight and the content of each ethylenically unsaturated bond are shown in Table 3. did.

Reference Example 1-11
A partially hydrogenated block copolymer (k) was prepared in the same manner as in Reference Example 1-5 except that isoprene was used instead of 1,3-butadiene as the second-stage polymerization component in Reference Example 1-5. Obtained. With respect to the obtained block copolymer (k), the structure and the weight average molecular weight, each constituent amount of the polymer blocks A and B, and each weight average molecular weight and the content of each ethylenically unsaturated bond are shown in Table 3. did.

Reference Example 1-12
An autoclave with an internal volume of 5 liters was charged with 2,400 g of degassed and dehydrated cyclohexane, 16.8 g of THF, 272 g of 1,3-butadiene, 28 g of isoprene, and 100 g of styrene, and then 0.80 g of nBuLi was added. The temperature rising polymerization from 0 ° C. to 80 ° C. was performed. After confirming that the polymerization conversion rate was 100%, 0.682 g of dimethyldichlorosilicon was added and a coupling reaction was performed for 15 minutes. Next, half of the obtained polymerization solution was blown down, 3.5 g of 2,6-di-tert-butylcatechol was added, and the solvent was removed by steam distillation. Then, it dried at 110 degreeC using the hot roll, and the polymer (l) which was not hydrogenated and was coupled was obtained. Table 3 shows the structure and weight average molecular weight, the constituent amount of the polymer block A, the weight average molecular weight, and the content of ethylenically unsaturated bonds for the obtained copolymer (l).

Reference Example 1-13
Using the remaining half of the polymerization solution obtained in Reference Example 1-3, hydrogenation of a styrene / isoprene / butadiene terpolymer having a random structure was performed by hydrogenation in the same manner as in Reference Example 1-1. A coalescence (m) was obtained. With respect to the obtained copolymer (m), the structure, the weight average molecular weight, the constituent amount of the polymer block A, the weight average molecular weight, and the content of ethylenically unsaturated bonds are shown in Table 3.

Reference Example 1-14
A hydrogenated block copolymer (in the same manner as in Reference Example 1-9) except that the initial amount of THF was increased 10 times and THF was not added at the time of addition of the monomer added after the second stage. n) was obtained. Regarding the obtained block copolymer (n), the structure and the weight average molecular weight, the constituent amounts of the polymer blocks A and B, and the weight average molecular weight and the content of each ethylenically unsaturated bond are shown in Table 4. did.

Reference Examples 1-15 and 1-16
Reference Example 1-1 except that the types of monomer compounds used for obtaining the block copolymer before hydrogenation and the amounts thereof used, the amounts of nBuLi and THF used were varied as shown in Table 4. Similarly, a polymerization reaction and a hydrogenation reaction were carried out to obtain block copolymers (o) and (p). About each obtained block copolymer, the structure and weight average molecular weight, each component of polymer blocks A and B, and each weight average molecular weight and content of each ethylenically unsaturated bond were written together in Table 4.

2. Production of rubber composition and its evaluation
Experimental Example 2-1～2- 5 and Experimental Examples 3-1～3-11
The block copolymer or copolymer obtained above, carbon black (trade name “Dia Black N339”, manufactured by Mitsubishi Chemical Corporation), silica (trade name “Nipsil AQ”, manufactured by Tosoh Silica Co., Ltd.), and silane A coupling agent (trade name “Si75”, manufactured by Degussa) was charged into a kneading machine (trade name “Lab Plast Mill”, manufactured by Toyo Seiki Co., Ltd.) at the ratio shown in Tables 5 to 7, and 90 to 145 ° C. Kneaded. Thereafter, the kneaded rubber is dumped once, and further sulfur, vulcanization accelerator (i) (trade name “NOCCELER DM”, manufactured by Ouchi Shinsei Chemical Co., Ltd.), vulcanization accelerator (ii) (trade name “NOCCELER TTTE” “Ouchi Shinsei Chemical Industry Co., Ltd.) was added and kneaded in the same kneader. Next, vulcanized products were obtained by vulcanization with various evaluation molds having a predetermined shape and size.
Using this evaluation vulcanizate, workability, tensile strength, Lambourne abrasion index, ozone resistance and heat aging resistance were evaluated. The results are shown in Tables 5-7.
The Lambourn wear index was expressed as an index with the value of Experimental Example 3-7 as 100. Higher values mean better wear resistance.

Table 7 shows the following. That is, Experimental Example 3-5 is an example using a block copolymer (j) outside the scope of the present invention, and is inferior in tensile strength, wear resistance, ozone resistance and heat aging resistance. Experimental Example 3-6 is an example using a block copolymer (k) outside the scope of the present invention. Similar to Experimental Example 3-5 , tensile strength, wear resistance, ozone resistance and heat aging resistance are used. Inferior to Experimental Example 3-7 is an example using the polymer (l) containing only the polymer block A, and is inferior in tensile strength, ozone resistance and heat aging resistance. Experimental Example 3-8 is an example using the polymer (m) containing only the polymer block A, and is inferior in tensile strength and wear resistance. Experimental Example 3-9 is an example using a block copolymer (n) that is outside the scope of the present invention, and is inferior in tensile strength and heat aging resistance. Experimental Examples 3-10 is an example of using the block copolymer outside the scope of the present invention (o), too little polymer block B ¹ as a non-crosslinking spacer (too short) control between crosslinking points Therefore, the cross-linked product is inferior in tensile strength and abrasion resistance. Experimental Examples 3-11, respectively Mw of the polymer block ^{A 1} and ^{A 2} is an example of using smaller block copolymer 700, and 600 (p), the chain length of the polymer block A is too short Since sufficient crosslinking cannot be formed, the tensile strength and wear resistance are poor.
On the other hand, from Tables 5 and 6, Experimental Examples 2-1 to 2-2 and Experimental Examples 3-1 to 3-3 have good workability, tensile strength, wear resistance, ozone resistance, and heat aging. It can be seen that the balance of physical properties is excellent.

The rubber composition of the present invention is excellent in tensile strength, abrasion resistance, ozone resistance and heat aging resistance by crosslinking, and a molded product using the rubber composition is a rubber for tires such as treads, sidewalls, and carcass. It is useful as a product, anti-vibration rubber, various belts, various rollers, various sealing materials and the like.

Claims (14)

A rubber composition comprising a block copolymer and carbon black,
The block copolymer comprises two polymer blocks having an ethylenically unsaturated bond, and another polymer block between the polymer blocks, and the polymer block having the ethylenically unsaturated bond comprises When A ¹ and A ² (A ¹ and A ² may be the same or different) and the other polymer block is B, (A ¹ -B-A ² ) _s X Wherein s is an integer selected from 1 to 6 and X is a residue of a coupling agent.
The polymer block A ¹ is composed of a conjugated diene compound and includes a monomer unit (a11) including a 1,4-bond, and 80% or more of unsaturated bonds derived from the conjugated diene compound are ethylenically unsaturated. A polymer block included as a bond,
The polymer block B includes a monomer unit (b11) composed of a conjugated diene compound and a monomer unit (b12) composed of an aromatic vinyl compound, and 0 to 20 unsaturated bonds derived from the conjugated diene compound. % Is a polymer block containing as ethylenically unsaturated bonds,
It said polymer block A ² contains a monomer unit (a21) containing it and 1,4-linked conjugated diene compound, 80% or more of unsaturated bonds derived from the conjugated diene compound is an ethylenically unsaturated A polymer block included as a bond,
The polymer block having an ethylenically unsaturated bond has a weight average molecular weight in the range of 1,000 to 20,000,
A rubber composition wherein the weight average molecular weight of the other polymer block is in the range of 5,000 to 100,000.   The total constituent amount of the polymer block having the ethylenically unsaturated bond is 1 to 80% by mass with respect to the block copolymer, and the total constituent amount of the other polymer block is the block. The rubber composition according to claim 1, wherein the content is 99 to 20% by mass based on the copolymer.   The weight average molecular weight of the block copolymer is in the range of 7,000 to 1,000,000, and the ratio of the weight average molecular weight and the number average molecular weight is in the range of 1 to 5. Rubber composition. The conjugated diene compound used to form the polymer block A ¹ and the polymer block A ² is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3. The rubber composition according to any one of claims 1 to 3, which is at least one selected from butadiene and 1,3-pentadiene. The conjugated diene compound used for forming the polymer block B is at least one selected from 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene,
The aromatic vinyl compound used to form the polymer block B is styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropyl. The rubber composition according to any one of claims 1 to 4, which is at least one selected from styrene and 4-tert-butylstyrene.   The rubber composition according to any one of claims 1 to 5, wherein a content of the carbon black is 20 to 120 parts by mass with respect to 100 parts by mass of the block copolymer.   A molded article obtained by using the rubber composition according to any one of claims 1 to 6. A rubber composition comprising a block copolymer and silica,
The block copolymer comprises two polymer blocks having an ethylenically unsaturated bond, and another polymer block between the polymer blocks, and the polymer block having the ethylenically unsaturated bond comprises A ¹ and A ² (where A ¹ and A ² may be the same or different), and when the other polymer block is B, A ¹ -B-A ² -BA ¹ structure,
The polymer block A ¹ is a monomer unit (a11) made of a conjugated diene compound and containing a 1,4-bond, or a monomer unit made of the monomer unit (a11) and an aromatic vinyl compound. A polymer block containing both of (a12), wherein 80% or more of unsaturated bonds derived from the conjugated diene compound are contained as ethylenically unsaturated bonds;
The polymer block B includes a monomer unit (b11) composed of a conjugated diene compound and a monomer unit (b12) composed of an aromatic vinyl compound, and 0 to 20 unsaturated bonds derived from the conjugated diene compound. % Is a polymer block containing as ethylenically unsaturated bonds,
Said polymer block A ² is monomeric units containing it and 1,4-linked conjugated diene compound (a21), or consist of said monomer units (a21) and the aromatic vinyl compound monomer unit (A22) is a polymer block containing both of the unsaturated bonds derived from the conjugated diene compound and containing 80% or more of ethylenically unsaturated bonds,
The polymer block having an ethylenically unsaturated bond has a weight average molecular weight in the range of 1,000 to 20,000,
A rubber composition wherein the weight average molecular weight of the other polymer block is in the range of 5,000 to 100,000 .   The total constituent amount of the polymer block having the ethylenically unsaturated bond is 1 to 80% by mass with respect to the block copolymer, and the total constituent amount of the other polymer block is the block. The rubber composition according to claim 8, which is 99 to 20% by mass with respect to the copolymer.   The weight average molecular weight of the block copolymer is in the range of 7,000 to 1,000,000, and the ratio of the weight average molecular weight and the number average molecular weight is in the range of 1 to 5. Rubber composition. The conjugated diene compound used to form the polymer block A ¹ and the polymer block A ² is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3. The rubber composition according to any one of claims 8 to 10, which is at least one selected from butadiene and 1,3-pentadiene. The conjugated diene compound used for forming the polymer block B is at least one selected from 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene,
The aromatic vinyl compound used to form the polymer block B is styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropyl. The rubber composition according to any one of claims 8 to 11, which is at least one selected from styrene and 4-tert-butylstyrene.   The rubber composition according to any one of claims 8 to 12, wherein a content of the silica is 20 to 140 parts by mass with respect to 100 parts by mass of the block copolymer.   A molded article obtained by using the rubber composition according to any one of claims 8 to 13.